Sökning: "Extraction technique"

Visar resultat 1 - 5 av 237 avhandlingar innehållade orden Extraction technique.

1. 1. Pressurized Fluid Extraction : A Sustainable Technique with Added Values

   Författare :Monica Waldebäck; Karin Markides; Åke Bergman; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; ASE; biomass; green chemistry; household waste; lipid; pesticide; PFE; pressurized fluid extraction; sediment; Analytisk kemi; Analytical chemistry; Analytisk kemi;

   Sammanfattning : The challenge for the future was defined by the Brundtland Commission (1987) and by the Rio Declaration (1992), in which the fundamental principles for achieving a sustainable development were provided. Sustainable chemistry can be defined as the contribution of chemistry to the implementation of the Rio Declaration. LÄS MER

3. 2. Recent Extraction Techniques with Emphasis on Supercritical Fluid Extraction and Microwave-assisted Extraction

   Författare :Cecilia Sparr Eskilsson; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytisk kemi; Analytical chemistry; Pressurized hot water extraction; Pressurized liquid extraction; Microwave-assisted extraction; Recent extraction techniques; Supercritical fluid extraction;

   Sammanfattning : Today’s requirements of fast, reliable and selective analytical methods with minimal usage of organic solvents have accelerated the development of new, automated extraction techniques. In this thesis recent extraction techniques with emphasis on supercritical fluid extraction (SFE) and microwave-assisted extraction (MAE) were investigated. LÄS MER

4. 3. Analysis of Acrylamide and Anthocyanins in Foods : Extraction Optimization for Challenging Analytes

   Författare :Erik V. Petersson; Charlotta Turner; Johan Rosén; Rolf Danielsson; Marja-Liisa Riekkola; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analysis; Extraction; Optimization; Acrylamide; Anthocyanins; Foods; Challenges; Analytical chemistry; Analytisk kemi; Analytical Chemistry; Analytisk kemi;

   Sammanfattning : In this thesis, the main concern has been to improve the reliability of different parts of the analytical workflow (Paper I, II, IV &V). Additionally, one of the resulting optimized methods was used in a real application (Paper III). Paper I-II concerned the extraction of acrylamide (AA) from foods. LÄS MER

5. 4. New methods for determination of airborne pollutants : Focus on tetrabromobisphenol A, organophosphate triesters and polycyclic aromatic hydrocarbons

   Författare :Johanna Tollbäck; Ulrika Nilsson; Peter Haglund; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Air sampling; sampling methods; indoor air; SPE; SPME; extraction; dynamic extraction; online coupling; SWE; subcritical water extraction; GC MS; LC MS; organophosphate triesters; PAH; tetrabromobisphenol A; Analytical chemistry; Analytisk kemi; Analytical Chemistry; analytisk kemi;

   Sammanfattning : The work presented in this thesis concerns the development and evaluation of new methods of sampling and analysis of organic pollutants in the indoor and outdoor environment. In Paper I, the development of a new method was reported for the determination of the brominated flame retardant tetrabromobisphenol A (TBBPA) in air using sampling with glass fiber filter and polyurethane foam (PUF), ultrasonic solvent extraction and liquid chromatography coupled to electrospray ionisation mass spectrometry (LC-ESI/MS). LÄS MER

7. 5. Optimisation Challenges in Pressurised Hot Water Extraction of Polyphenols: Extraction and Degradation Kinetics

   Författare :Jiayin Liu; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Extraction kinetics; degradation kinetics; pressurised hot water extraction; optimisation; and anthocyanins; flavonoids; and polyphenols;

   Sammanfattning : Pressurised hot water is an environmentally friendly alternative to hazardous organic solvents such as methanol and heptane. One of the many applications of using pressurised hot water extraction (PHWE) is to extract polyphenols from plants. The challenges in PHWE lies with the optimisation of extraction yield. LÄS MER